Is the following sentence grammatically correct?
An apple is red and has a spherical shape.
In comparison, I'm pretty sure that the following sentences are correct:
- An apple is red and green.
- An apple has a spherical shape and smells like fish.
This is an example of Conjunction Reduction. The base sentence is An apple is red and an apple has a spherical shape. This is two sentences with indefinite generic subject noun phrase an apple and different verb phrases is red and has a spherical shape. They're both grammatical, so their conjunction is too. Then the generic subject an apple gets deleted because it's identical in both clauses. And that's all. The verb phrases are different, so they stay. Simple. – John Lawler